# *-* coding:utf8 *-*
from PyQt5.QtWidgets import * 
import sys
app = QApplication([])
widget = QWidget()

def showMsg():
    QMessageBox.information(widget,"信息提示框","OK,弹出测试信息")

btn =  ("点击测试按钮",widget)
btn.clicked.connect(showMsg)
widget.show()
sys.exit(app.exec_())